Approximately 15 million American children suffer from psychiatric disorders at an estimated treatment cost of $8.9 billion annually. During the last 30 years several effective evidence-based treatments (EBTs) have been developed to treat these conditions. However, EBTs are rarely implemented successfully in usual care practice settings. Given the typically poor outcomes of usual care services, the National Institute of Mental Health recently prioritized research that develops and tests implementation strategies to effectively integrate EBTs within community settings. Implementation researchers have tested a range of implementation strategies in mental health settings but two key knowledge gaps limit the field. First, researchers have yet to identify the specific change processes (i.e., the require active ingredients of implementation interventions), or the specific change mechanisms (i.e., the intermediate changes that occur during the course of the intervention and serve as the basis for the effect) that explain how and why implementation strategies generate desired changes. Identification of change processes and mechanisms is critical to developing the most effective and efficient implementation strategies for targeted settings. Second, although most mental health services are provided within complex organizations and decades of research suggest organizational social context is vital to successful innovation implementation, few implementation strategies target social context. The next steps in advancing the development of effective implementation strategies involve understanding how successful implementation strategies generate their effects, and specifically addressing the role of social context in the cross-level organizational change that characterizes successful EBT implementation. The proposed research training plan enables the PI to develop an independent program of research focused on identifying the organizational change processes and mechanisms that contribute to effective integration of EBTs into routine clinical settings. The research training plan includes advanced training activities that develop the PI's competency across three core areas: implementation science, organizational interventions, and organizational change mechanisms. The plan includes specialized didactic learning activities (elective coursework, workshops, and conferences), collaboration with three expert implementation scientists who are each directing NIMH-funded R01 implementation studies, and completion of an independent research project. The research project is the first to directly test organizational change processes and change mechanisms in the context of a randomized controlled trial of an organizational implementation strategy. The training plan prepares the PI for an independent research career focused on improving the implementation of effective mental health treatments in usual care settings. The likely benefits of this research include enhanced quality of life for children with psychiatric disorders and their families and reduced costs of mental health treatment through greater efficiency and effectiveness of service systems.